That stuff, "Poultry Protector," will not treat an infestation. It is a preventative, not a treatment.
Use (Permethrine) Poultry Dust. It works well. However, one treatment is not enough. You must treat again in a week. I have read where many do the dust treatment each week for 3 or 4 weeks. This assures that the (lice and mites) eggs are killed and not hatched.
Also, be sure to clean your premises thouroughly. Everything must come out of the coop .... dust and clean, and then treat the coop as well. All new bedding. It works well to sprinkl Sevin Dest or Poultry Dust in the new bedding too. The roosts must be cleaned and sanded down and treated. (Adams Flea and Tick Spray works well for this also.)
Good luck!